JP5782938B2 - Combustion device - Google Patents

Description

  The present invention relates to a combustion apparatus equipped with a heat exchanger for recovering latent heat, and in particular to a technique for preventing scattering of condensed water when exhaust gas that has passed through the heat exchanger for recovering latent heat is exhausted from an exhaust outlet. Related.

  In recent years, as a combustion device, a primary heat exchanger for heat exchange heating with combustion heat of a combustion burner, and a secondary heat exchanger for recovering latent heat from combustion exhaust gas after heat exchange with this primary heat exchanger A so-called condensing type device having a (heat exchanger for latent heat recovery) is known. In such a condensing type, the water vapor in the exhaust gas is condensed by the contact between the exhaust gas and the latent heat recovery heat exchanger, and strongly acidic condensed water (drain water) is generated. On the other hand, in the condensing type, a space for arranging the heat exchanger for collecting latent heat is required. Combustion noise and noise generation due to passage of exhaust gas are likely to occur.

  For this reason, mainly for the purpose of noise suppression, an exhaust passage extending from the outlet of the heat exchanger chamber in which the latent heat recovery heat exchanger is accommodated to the exhaust outlet is formed on an inclined slope that rises toward the exhaust outlet. (For example, refer to Patent Documents 1 and 2) or to form an upward crank-shaped bent path (for example, refer to Patent Document 3).

JP 2007-232289 A JP 2009-243725 A JP 2007-33001 A

  However, if the exhaust passage is configured so that the exhaust gas emitted from the heat exchange chamber rises on the ramp or the like, a part of the drain water originally intended to be neutralized by flowing down from the bottom near the outlet of the heat exchange chamber Is trapped in the exhaust gas flowing into the exhaust passage as water droplets, and the drained water is likely to be scattered on the flow of the exhaust gas from the exhaust port to the outside.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide external drain water while suppressing noise in a combustion apparatus equipped with a latent heat recovery heat exchanger. An object of the present invention is to provide a combustion apparatus capable of preventing scattering.

  In order to achieve the above object, in the present invention, a latent heat recovery heat exchanger is provided, which is disposed above the exhaust outlet from the exhaust outlet of the heat exchange chamber in which the latent heat recovery heat exchanger is accommodated. The following specific matters were provided for the combustion apparatus connected to the exhaust port by an exhaust passage extending obliquely upward. That is, the exhaust passage includes an upper inclined plate and a lower inclined plate. As the lower inclined plate, a rising portion that rises substantially vertically from the bottom of the heat exchange chamber, and the exhaust from the upper end of the rising portion. An inclined portion extending obliquely upward toward the mouth is provided. A water droplet prevention plate is disposed at a position near the heat exchange chamber of the rising portion with a gap space between the rising portion and substantially parallel to the rising portion. The exhaust outlet of the heat exchange chamber is defined by the upper end portion of the water droplet prevention plate and the lower end portion of the upper inclined plate (Claim 1).

  In the case of the present invention, the drain water is condensed on the surface of the latent heat recovery heat exchanger by the latent heat recovery from the exhaust gas in the heat exchange chamber, and the water droplets of this drain water are entrained in the exhaust gas flow and flow toward the exhaust outlet side. However, after the exhaust gas in a state where the water droplet is entrained collides with the water droplet prevention plate, the flow direction is changed upward to flow into the exhaust passage from the exhaust outlet. At this time, the exhaust gas flow collides with the water droplet prevention plate, so that the water droplets entrained in the exhaust gas can be attached to the water droplet prevention plate and dropped along the water droplet prevention plate. The exhaust gas after being made can flow into the exhaust passage. As a result, the occurrence of a situation in which drain water is scattered by the exhaust gas discharged from the exhaust port can be reliably prevented.

  In the combustion apparatus of the present invention, the gap space is communicated with the exhaust passage through an upper surface opening facing the exhaust passage and opened upward, and between the water droplet prevention plate and the bottom of the heat exchange chamber, A communication opening communicating with the gap space may be provided (Claim 2). By doing in this way, in addition to being able to more reliably prevent the prevention of drain water scattering from the exhaust port, even if a water droplet prevention plate is installed, the exhaust resistance is eliminated as much as possible. The increase in noise generation can be prevented and noise reduction can be achieved. That is, even if a small amount of water droplets remain in the exhaust gas flowing into the exhaust passage from the exhaust outlet even if it collides with the water droplet prevention plate, even if a small amount of water droplets remain in the exhaust gas, Since the flow direction is forcibly changed toward the exhaust outlet on the side of the head, the momentum of the flow is cut and the top opening opens from the position beyond the upper end of the water droplet prevention plate The remaining water droplets can be dropped into the gap space from the upper surface opening and discharged from the communication opening on the bottom side. Moreover, even if the water droplet prevention plate is arranged close to the latent heat recovery heat exchanger, the gap space is communicated with the heat exchange chamber and the exhaust passage through the communication opening and the upper surface opening, so that the exhaust resistance is reduced. This can eliminate the increase and contribute to noise reduction.

  Further, in the combustion apparatus of the present invention, the lower end of the water droplet prevention plate is displaced in the front-rear direction from a virtual vertical line vertically lowered from the upper end thereof, and enters the overhanging state facing the heat exchange chamber side. It can arrange | position in the state which inclined like this (Claim 3). By doing in this way, the water droplet of the drain water which collided and adhered to the water droplet prevention board will be easy to peel off from the surface of a water droplet prevention plate, and it will become easy to drop a water droplet. This makes it easier to attach and separate water droplets from the exhaust gas that will collide thereafter, and it is possible to more reliably attach and separate water droplets due to the collision.

  As described above, according to the combustion apparatus of the present invention, it is possible to cause the exhaust gas flow including water droplets of the drain water to collide with the water droplet prevention plate, and the gas is entrained in the exhaust gas by the collision. Water droplets can be attached to the water droplet prevention plate and dropped along the water droplet prevention plate. For this reason, it becomes possible to allow the exhaust gas after the water droplets have been removed to flow into the exhaust passage, thereby reliably preventing the occurrence of a situation in which drain water is scattered by the exhaust gas discharged from the exhaust port. Can be prevented.

  In particular, according to claim 2, the gap space is communicated with the exhaust passage by the upper surface opening facing the exhaust passage and opened upward, and between the water droplet prevention plate and the bottom of the heat exchange chamber, By providing a communication opening that communicates, it will be possible to prevent the drain water from splashing from the exhaust port more reliably, and even if a water droplet prevention plate is installed, it will become an exhaust resistance. As much as possible, the noise generation is prevented from increasing and the noise can be reduced. In other words, even if a small amount of water droplets remain in the exhaust gas even if they collide with the water droplet prevention plate, the remaining water droplets can be dropped into the gap space from the top opening, and the water droplet prevention plate can be Even if it is placed close to the exchanger, the gap space can be communicated with the heat exchange chamber and the exhaust passage through the communication opening and the upper surface opening, contributing to noise reduction by eliminating an increase in exhaust resistance. It will be possible.

  According to the third aspect of the present invention, the water droplet prevention plate is inclined so that the lower end portion thereof is displaced in the front-rear direction from the virtual vertical line vertically dropped from the upper end portion thereof and is overhanging toward the heat exchange chamber side. By disposing it in a tilted state, the water droplets that collide with the water droplet prevention plate and adhere to it can be easily peeled off from the surface of the water droplet prevention plate, and the water droplets can be easily dropped. As a result, water droplets from exhaust gas that subsequently collide can be efficiently attached and easily separated, and water droplets can be attached and separated more reliably due to collision.

It is a section explanatory view of a combustion device concerning an embodiment of the present invention. It is the elements on larger scale which concern on the exhaust passage part of FIG. FIG. 3 is a partially enlarged view in which an exhaust passage portion of FIG. 2 is further enlarged. It is an expansion perspective view which shows the example of a specific shape of a water-drop prevention board.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a part of a hot water supply heat source device as a combustion apparatus according to an embodiment of the present invention, and the hot water supply heat source device is configured as a so-called condensing type (latent heat recovery type). That is, the combustion device passes through the combustion burner 2, the primary heat exchanger 3 that is heat-exchanged and heated by the combustion heat (sensible heat) of the combustion burner 2, and the primary heat exchanger 3 in the housing 1. A secondary heat exchanger (latent heat recovery heat exchanger) 4 that guides the exhaust gas and recovers the latent heat of the exhaust gas by heat exchange, and the exhaust gas after passing through the secondary heat exchanger 4 flows in, And an exhaust passage 5 for discharging the inflowing exhaust gas to the external space.

  The combustion burner 2 is housed in the burner case 21 and burns toward the upper combustion space in response to the supply of combustion air from the blower fan 22 and the supply of fuel (for example, fuel gas) from the fuel supply pipe 23. It has come to be. The primary heat exchanger 3 is housed in a primary heat exchanger case 31 connected to the upper side of the burner case 21, and the water after being preheated by passing through the secondary heat exchanger 4 in advance is the primary heat. Heat is exchanged by the combustion heat of the combustion burner 2 while flowing in one end of the exchanger 3 toward the other end and flowing in the primary heat exchanger 3.

  Between the primary heat exchanger case 31 and the secondary heat exchanger case 41 in which the secondary heat exchanger 4 is installed, the exhaust gas from the upper surface opening of the primary heat exchanger case 31 is transferred to the secondary heat exchanger. A passage case 6 in which an internal passage 61 is defined so as to be gathered and guided to the exhaust inlet 42 of the case 41 is interposed. In the passage case 6, the inner passage 61 spreads over the entire upper surface opening of the primary heat exchanger case 31 on its lower surface to collect exhaust gas from the primary heat exchanger 3, and then gradually toward the rear side upward. The exhaust gas (see the dotted arrow in FIG. 1) is guided to the exhaust inlet 42 on the back side of the secondary heat exchanger case 41.

  An exhaust top 7 is coupled to the front surface side of the secondary heat exchanger case 41 by a flange piece 71 around the exhaust top 7, and a heat exchange chamber 40 is defined in the interior. The heat exchange chamber 40 communicates with the internal passage 61 through the exhaust inlet 42 on the back side (right side in the drawing) and the exhaust passage 5 through the exhaust outlet 44 that also serves as an inflow port for the exhaust passage 5 on the front side (left side in the drawing). Communicate. The upstream end of the drain water collecting pipe 81 is opened at the bottom position on the front end side of the heat exchange chamber 40 and in the vicinity of the lower side of the exhaust outlet 44 of the heat exchange chamber 40, and the bottom wall from the secondary heat exchanger 4 and the like. The drain water falling on the upper surface of 45 is dropped into the drain water collecting pipe 81 to collect water.

  As the secondary heat exchanger 4 accommodated in the heat exchange chamber 40, various types can be adopted, but what is called a thin tube type or a multi-tube type is shown in the drawing. This is because a large number of thin tubes 43, 43,... Grouped for forward and return are arranged so as to traverse the inside of the secondary heat exchanger case 41. Are passed through a large number of tubules 43, 43,... For return, and passed through a plurality of tubules 43, 43,... For return from a folded header, and then passed from the return header to one end side of the primary heat exchanger 3. It comes to supply. When the exhaust gas introduced from the exhaust inlet 42 of the secondary heat exchanger case 41 passes to the exhaust outlet 44, it comes into contact with the numerous thin tubes 43, 43, ..., and the latent heat of the exhaust gas is heated. The heat is absorbed by the water in each thin tube 43 by the replacement, and the latent heat recovery is performed. Of course, as described above, the secondary heat exchanger 4 may be of a type other than the thin tube type.

  The exhaust passage 5 extends from an exhaust outlet 44 disposed at an intermediate position in the vertical direction of the heat exchange chamber 40 to an exhaust outlet 72 that opens at a front upper end position of the exhaust top 7. An inclined path that extends obliquely upward as a whole with respect to the exhaust port 72 is configured so that the exhaust gas flowing in from the outlet 44 flows obliquely upward toward the exhaust port 72 disposed above the exhaust outlet 44. The compartment is formed. Specifically, as shown in detail in FIGS. 2 and 3, the exhaust passage 5, which is a characteristic part of the present embodiment, includes an upper inclined plate 51 and a lower inclined plate 52. A passage space as an inclined path that is bent in an upward slope toward the exhaust port 72 is formed between the lower inclined plate 52 and the exhaust port 72. In addition, a water droplet prevention plate 53 is disposed on the exhaust outlet 44 side of the exhaust passage 5 (inflow side of the exhaust passage 5). Hereinafter, the left-right direction of the drawings will be described as the front-rear direction of the heat exchange chamber 40, the secondary heat exchanger case 41, the secondary heat exchanger 4, and the like.

  The upper inclined plate 51 includes an upper wall portion 512 whose upper end edge 511 hangs from the lower surface on the front end side of the top wall 46 of the secondary heat exchanger case 41 and partitions the front end side of the heat exchange chamber 40, and the upper wall portion 512. An upper inclined wall 514 is bent at an acute angle at the lower end edge (lower end) 513 in an “L” shape and is bent at an acute angle toward the exhaust port 72 and extends obliquely upward. After the upper inclined wall 514 is bent in the middle, the leading edge 515 is coupled to the exhaust top 7 so as to cover the upper side of the exhaust port 72. The lower inclined plate 52 has a rising edge 522 whose lower end edge 521 rises upward from the bottom wall 45 of the secondary heat exchanger case 41, and a lower inclined wall 524 that is bent at the upper end 523 of the rising edge 522 and extends obliquely upward. It consists of. Then, the lower inclined wall 524 is bent in the middle to change the inclined state stepwise or gently, and then the tip edge 525 is coupled to the exhaust top 7 so as to cover the lower side of the exhaust port 72. .

  The water droplet prevention plate 53 is in a state where a gap space 54 is separated from the rising portion 522 at a position (rear position) on the secondary heat exchanger 4 side of the rising portion 522 of the lower inclined plate 52, and The exhaust gas which is disposed substantially parallel to the rising portion 522 and flows forward in the lower side of the lowermost thin tube 43a at the front end position among the many thin tubes 43 constituting the secondary heat exchanger 4 in particular. It faces the flow F (see FIG. 3). The clearance space 54 has an upper surface facing the exhaust passage 5 and is communicated with the exhaust passage 5 through the upper surface opening 541, and is communicated with the bottom of the heat exchange chamber 40 through the communication opening 542 at the lower end position. . That is, the lower end portion 531 of the water droplet prevention plate 53 is positioned in a state where the lower end portion 531 is lifted by a predetermined dimension from the bottom wall 45 of the secondary heat exchanger case 41. Further, the water droplet preventing plate 53 has its lower end 531 (see FIG. 3) displaced forward (leftward in FIG. 3) by a predetermined angle α from the virtual vertical line V lowered from the upper end 532, and the upper end side is The exhaust gas flow F is disposed in an overhanging state and is inclined so as to face each other.

  Due to the opening between the upper end 532 of the water droplet prevention plate 53 and the lower end edge 513 of the upper inclined plate 51, the exhaust outlet 44 communicating with the exhaust passage 5 from the heat exchange chamber 40 is an intermediate region in the vertical direction of the heat exchange chamber 40. Will be formed. Further, such a water droplet prevention plate 53 is such that a later-described collision wall portion 533 causes water droplets to adhere by causing the exhaust gas flow F to collide with each other. It is preferable to arrange them close to each other with a narrow interval (for example, about 10 mm). In addition, the collision wall portion 533 hangs from the lower end edge 513 such that the collision wall portion 533 is disposed at a position (front position) closer to the exhaust top 7 than the lower end edge 513 of the upper wall portion 512 of the upper inclined plate 51. It is preferable when dropping the drain water drops onto the bottom wall 45.

  As a specific example of the shape of the water droplet prevention plate 53, the one shown in FIG. That is, the water droplet prevention plate 53 is formed by using a stainless steel plate material in consideration of corrosion prevention from drain water, and rises from the lower end portion 531 to the upper end portion 532, and the exhaust gas flow F collides. With the wall portion 533 as a main element, the upper end portion 532 of the collision wall portion 533 is bent at a substantially right angle to the front side (the left side in FIG. 4) on the exhaust top 7 side and extends substantially horizontally, and further obliquely upward. As a result, the inclined wall portion 534 extends along the upper surface of the lower inclined plate 52 (see also FIG. 3) by an appropriate size. In addition, an opening corresponding to the upper surface opening 541 is formed in a portion extending substantially horizontally from the upper end portion 532 of the collision wall portion 533, and both end edge portions of the collision wall 533 are bent forward from an appropriate intermediate position. Support portions 535 and 535 extending to the rising portion 522 of the lower inclined plate 52 are formed. The lower end portion 531 has a flange portion formed by bending the lower end edge for reinforcement in order to maintain the planar shape of the collision wall portion 533. The support portions 535 and 535 are joined to the rising portion 522 of the lower inclined plate 52, and the inclined wall portion 534 is joined to the lower inclined wall 524 of the lower inclined plate 52, and the water droplet preventing plate 53 is attached. ing.

  In addition, as the water droplet prevention plate 53, the collision wall part 533 should just be arrange | positioned in the predetermined position, and another part is not essential. That is, the collision wall portion 533 has a gap space 54 between the collision wall portion 533 and the rising portion 522 of the lower inclined plate 52, has a communication opening 542 below the gap space 54, and has an upper surface opening 541 on the upper side. What is necessary is just to be arrange | positioned.

  In the case of the exhaust passage 5 described above, the following operational effects are obtained. That is, while the exhaust gas flows into the heat exchange chamber 40 from the exhaust inlet 42 and travels to the exhaust outlet 44, drain water is condensed on the surface of the secondary heat exchanger 4 due to latent heat recovery from the exhaust gas. More drain water falls to the bottom wall 45 from the lowermost thin tube 43a at the front end position. For example, the water droplets of the drain water are entrained in the exhaust gas flow F (see FIG. 3), and the exhaust gas entrained with the water droplets collides with the collision wall portion 533 of the water droplet prevention plate 53, and then the flow direction is directed upward. Instead, it flows into the exhaust passage 5 from the exhaust outlet 44. At this time, the exhaust gas flow F collides with the collision wall portion 533, so that water droplets entrained in the exhaust gas adhere to the collision wall portion 533, and the adhered water droplets adhere to the bottom wall 45 along the collision wall portion 533. While falling and collecting water in the drain water collecting pipe 81, the exhaust gas after the water droplets are removed flows into the exhaust passage 5 from the exhaust outlet 44. As a result, it is possible to reliably prevent the occurrence of a situation in which drain water is scattered by the exhaust gas discharged from the exhaust port 72 through the exhaust passage 5.

  Further, even if a small amount of water droplets remain in the exhaust gas flowing into the exhaust passage 5 from the exhaust outlet 44, the force of the flow is increased by colliding with the collision wall 533 and forcibly changing the flow direction upward. In addition, since the upper surface opening 541 is opened from the position of the upper end portion 532 of the collision wall portion 533, the remaining water drops also fall into the gap space 54 from the upper surface opening 541. As a result, it is possible to more reliably prevent the drain water from being scattered from the exhaust port 72. Further, although the collision wall portion 533 is disposed at a relatively close position facing the lower end position of the secondary heat exchanger 4, the rear (front side) thereof communicates with the exhaust passage 5 through the upper surface opening 541. Since the gap space 54 communicating with the heat exchange chamber 40 through the communication opening 542 is defined, exhaust resistance can be eliminated as much as possible, and noise generation can be prevented from increasing and noise reduction can be achieved.

<Other embodiments>
In addition, this invention is not limited to the said embodiment, Other various embodiment is included. That is, in the above-described embodiment, the collision wall portion 533 is inclined in an overhanging state so that water droplets of drain water adhering to the collision are likely to fall. It is preferable to do. In addition, even if it is not strictly vertical but is disposed at an inclination opposite to that of the above-described embodiment, the drain water attached by the collision can be transmitted and flowed down.

2 Combustion burner 4 Secondary heat exchanger (heat exchanger for latent heat recovery)
5 Exhaust passage 40 Heat exchange chamber 44 Exhaust outlet 51 Upper inclined plate 52 Lower inclined plate 53 Water droplet prevention plate 54 Gap space 72 Exhaust port 513 Lower end edge (lower end portion of upper inclined plate)
522 Rising part 523 Lower inclined wall (inclined part)
532 Upper end (upper end of water droplet prevention plate)
541 Upper surface opening 542 Communication opening

Claims (3)

Connected by an exhaust passage extending obliquely upward from the exhaust outlet of the heat exchange chamber containing the latent heat recovery heat exchanger to the exhaust outlet located above the exhaust outlet. A combustor, comprising:
The exhaust passage includes an upper inclined plate and a lower inclined plate,
The lower inclined plate includes a rising portion that rises substantially vertically from the bottom of the heat exchange chamber, and an inclined portion that extends obliquely upward from the upper end of the rising portion toward the exhaust port,
A water droplet prevention plate is disposed at a position near the heat exchange chamber of the rising portion, with a gap space between the rising portion and substantially parallel to the rising portion,
An exhaust outlet of the heat exchange chamber is defined by an upper end portion of the water droplet prevention plate and a lower end portion of the upper inclined plate,
Combustion device characterized by that. The combustion device according to claim 1,
The clearance space communicates with the exhaust passage through an upper surface opening that faces upward toward the exhaust passage, and communicates with the clearance space between the water droplet prevention plate and the bottom of the heat exchange chamber. A combustion device provided with a communication opening. The combustion apparatus according to claim 1 or 2, wherein
The water droplet prevention plate is disposed in an obliquely inclined state so that the lower end portion is displaced in the front-rear direction from the virtual vertical line vertically lowered from the upper end portion and faces the heat exchange chamber so as to be overhanged. Is a combustion device.

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